The present invention relates to a control device for the movement of a visual cursor on a monitor.
Typically, such a control device is called and electronic mouse or a track ball. An electronic mouse is usually moved over a surface on a rolling ball with the cursor tracking the movements of the mouse. A track ball, on the other hand, is typically stationary, with the cursor tracking the movement of the track ball in its housing.
The movement of the ball is typically monitored by the use of two shafts which are spring loaded against the ball and rotate when the ball is rotated, to give rotational movements along two different axes of rotation of the ball. Each of the shafts will have an encoder wheel connected to it.
With the development of laptop computers, it is desirable to have a track ball, since it is not often possible to have a separate surface for using a mouse, such as on an airplane. Since the track ball is stationary, it is ideally suited for such uses. It is desirable to mount a track ball on the keyboard for the computer.